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| <== Date ==> | <== Thread ==> |
|---|
| Subject: | Re: MRF Delay Compensation Function |
| From: | Javier Cereijo García via Tech-talk <tech-talk at aps.anl.gov> |
| To: | Michael Davidsaver <mdavidsaver at gmail.com>, "Shen, Guobao" <gshen at anl.gov> |
| Cc: | Timo Korhonen <Timo.Korhonen at esss.se>, Tech-Talk <tech-talk at aps.anl.gov> |
| Date: | Thu, 20 Feb 2020 09:40:06 +0100 |
Hi all,Yes, here at ESS we have done some tests in the lab in the past, although they were quite simple. I can share what we have learnt. These tests were done using mTCA-EVR-300 and mTCA-EVM-300, not VME.
The first feeling is that everything works as expected, and changing the target delay works smoothly, as well as changing the length of the optical fiber. There is one thing though that seems strange to me, and it is that the target delay must always be set so that it is greater than the physical delay, including internal delays. Otherwise some events will be missed. Even when using a 230-series EVG with the delay compensation disabled on the EVR side the target delay needs to be set correctly.
We didn't perform any complex jitter test, although monitoring the "DC lock" shows that it gets unlocked from time to time, usually recovering quickly. We didn't worry too much at that moment, the measured delay wasn't changing that quickly, I think that the lock monitor is quite sensitive. I can't recall from the top of my head if we were using the EVM's fractional synthesizer or an external RF source, so this may easily disappear in a more stable environment.
We are starting the commissioning phase soon so we will have better results. Best regards, Javier On 19/02/2020 18:17, Michael Davidsaver wrote:
On 2/18/20 10:43 AM, Shen, Guobao via Tech-talk wrote:Hi all, Is there anyone who has been using MRF EVM-300 delay compensation function for any purpose, in the lab, test stand, real machine, etc?ESS did some testing as well.If yes, would you mind to share us your experience?As I recall, it worked well on a test stand. My personal knowledge ends there.Thanks, Guobao-------- Guobao Shen gshen at anl.gov <mailto:gshen at anl.gov> Controls Group Leader Advanced Photon Source Argonne National Laboratory 9700 S. Cass Avenue, Lemont, IL 60439
-- Javier Cereijo García Embedded System Engineer HW&I group, ICS division European Spallation Source ERIC Mobile: +46 (0)72 179 23 34 E-mail: javier.cereijogarcia at ess.eu